Nature Gardens at NHM: LA's Urban Nature

Last week, Tania Perez, who is on our Museum education staff, found a cockroach crawling on our office wall! Said roach was quickly trapped and contained and was waiting for me when I got back to my office. Here in North America we have 55 species of cockroach (there are 3500 total in the world)! Of these 55 species, six in California are considered pests. The American Cockroach is the largest of these six roaches, with individuals reaching a maximum of 2 inches in length. Surprisingly, this roach isn't from America at all. It actually native to Africa. The species is also known as the ship cockroach and has hitched rides on ships traveling from Africa to the U.S. A likely apocryphal story, it paints the picture in such a way as to imply it was slave ships during the 1600s that inadvertently transported these insects to our shores.

I was recently out and about in the garden and found some fascinating insects, Keelbacked Treehoppers, Antianthe expansa. They were on some of our celery plants and are, according to Vanessa Vobis Master Gardener and Museum Gallery Interpreter, "a very annoying pest on our tomatoes."

Adult Keelbacked Treehopper on celery

(Approximately ¼ inch or 7 mm long)

When I found the Keelbacked Treehoppers, all but one were in the nymphal (immature) stage. As nymphs, these insects do not have wings (this is true for all insects—just look at caterpillars, grubs, and maggots), and are bound to the area in which they were deposited as eggs by their mother. The nymphs are often attended by ants, which feed on their sugary excreta and provide a level of defense against the treehopper's predators....